Projection apparatus with three light source units to output light bundles into an integrating tunnel from a direction nonparallel to output direction

ABSTRACT

A projection apparatus having three light source units optically coupled to an integrating tunnel. The three light source units to output three different color light bundles of different wavelengths into the integrating tunnel from a direction nonparallel to the output direction of the integrating tunnel.

FIELD OF THE INVENTION

The present invention is related to the field of multimedia devices,and, more particularly, to digital projection systems.

BACKGROUND OF INVENTION

Historically, projection apparatuses or engines of projection systemshave been designed employing high intensity discharge lamps. These priorart projection engines/systems suffer from a number of disadvantages.For example, the lamps typically have relatively short lives and reducedbrightness after an initial period of usage. Further, there is anappreciable period of waiting for the lamp to warm up, when a projectionengine/system is first turned on. During that period, either no image isavailable or the available images are of poor quality. Additionally,active cooling arrangements are typically required to dissipate the heatcreated during operation.

Resultantly, there has been a substantial interest in developing andmanufacturing in a mass scale, projection engines and projection systemsemploying solid state light sources. Such engines/systems typicallyeither do not have or have the aforementioned disadvantages to a lesserdegree.

In addition, there has been a general trend in the field of projectionsystems as well as throughout the electronic industry to make electronicsystems more compact and more efficient.

FIG. 1 illustrates a plane view of a typical solid state light sourceand micro mirror light valve based projection system architecture. Theplane view may be a top view or a side view of the projection system. Asillustrated, solid state light source based projection system 100includes a number of primary color solid state light sources, such aslight emitting diode (LED) 102, 104 and 106 sourcing red (R), green (G)and blue (B) lights respectively. LED 102, 104 and 106 are arranged inan orthogonal manner, respectively disposed on three sides of a dichroiccombiner 108. Dichroic combiner 108 is employed to combine the lightsemitted by LED 102, 104 and 106. Further, light integrator 110 is placedin the light path to enhance the combined light. A mirror 112 isemployed to reflect the enhanced light onto a micro mirror device 114.

The micro mirror device 114, otherwise known as a light valve device,includes a number of micro-mirrors that may be individually tilted to an“on” or an “off” position to selectively reflect the enhanced lightreflected from mirror 112 towards projection lens 116 (“on”) or awayfrom projection lens 116 (“off”). Resultantly, with each micro mirrorcorresponding to a pixel, and by selectively controlling theirpositions, an image or a series of images, including a series of imagesforming a motion picture, may be projected.

While the architecture of FIG. 1 works well, it is neverthelessdesirable to further improve on reducing the cost and/or increasingreliability of the next generation of projection engines and projectionsystems.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will be described referencing theaccompanying drawings in which like references denote similar elements,and in which:

FIG. 1 illustrates a plane view of a typical prior art solid state lightsource based projection engine/system;

FIG. 2 illustrates a block diagram view of a projection system inaccordance with various embodiments;

FIG. 3 illustrates an isometric view of an illumination module inaccordance with various embodiments;

FIG. 4A illustrates a particular embodiment of a light source unitdepicted in FIG. 3 in accordance with various embodiments;

FIG. 4B illustrates the light source unit and integrating tunneldepicting in FIG. 4A, in further detail, in accordance with variousembodiments;

FIG. 5 illustrates an illumination module in accordance with variousembodiments; and

FIG. 6 illustrates an illumination module in accordance with variousembodiments.

DETAILED DESCRIPTIONS OF EMBODIMENTS OF THE INVENTION

In the following detailed description, various aspects of theembodiments of the invention will be described. However, it will beapparent to those skilled in the art that other embodiments may bepracticed with only some or all of these aspects. For purposes ofexplanation, specific numbers, materials and configurations are setforth in order to provide a thorough understanding of these embodiments.However, it will also be apparent to one skilled in the art that otherembodiments may be practiced without the specific details. In otherinstances, well-known features are omitted or simplified in order not toobscure the description.

In the description below, references will be made to different colorlights or light bundles of different colors such as the primary colorsof red, green and blue. In referring to these color lights or colorlight bundles, it is to be understood that each of these color lights orcolor light bundles may be associated with electromagnetic radiationhaving wavelengths that may be associated with specific colors.

According to some embodiments of the invention, an illumination moduleis provided that may be compact and efficient at generating lightbundles. Such an apparatus may be incorporated into, for example, aprojection system.

Referring to FIG. 2, which is a block diagram depicting a projectionsystem according to some embodiments of the invention. The projectionsystem 200 may be used to generate, for example, motion picture and/orstill picture images onto a screen. For these embodiments, theprojection system 200 includes a control block 202, an illuminationmodule 204, a light valve device 206 and projection lens 208. For theembodiments, the control block 202 may be electrically coupled to theillumination module 204 and the light valve device 206. The illuminationmodule 204 may be optically coupled to the light valve 206, which mayfurther be optically coupled to a projection lens 208. Although notdepicted, in other embodiments, other components may be included in theprojection system 200 including, for example, a variety of opticalcomponents such as lens, light pipes, mirrors, prisms, polarizers, andthe like, power supply components and control components.

The illumination module 204 may generate light bundles of differentcolors and transmit the light bundles to the light valve 206 accordingto some embodiments. The light valve 206 may then direct the lightbundles to the projection lens 208, which allows the light bundles topass through and project onto, for example, a screen. Although theoptical light path 210 in FIG. 2 is depicted as being straight, in otherembodiments, the optical light path 210 may not be straight but insteadmay have twists and turns. That is, the light bundles generated by theillumination module 204 may be redirected by various optical componentssuch as mirrors, prisms, and the like.

The illumination module 204 may comprise of several componentsincluding, for example, a light integrator such as a light tunnel orintegrating tunnel and one or more light sources such as solid statelight sources. Other components such as mirrors, prisms, lenses, and thelike, may also be included in the illumination module 204.

The illumination module 204, according to some embodiments, may generatelight bundles of different colors such as the primary colors (i.e., red,green and blue), each light bundle comprising of specific colored lightcorresponding to specific electromagnetic wavelengths. The light bundlesgenerated by the illumination module 204 may be shaped to reflect theshape of the light valve device 206. For example, since the imagesproduced by a projection system may be projected onto a rectangularscreen, the light valve device may have a rectangular shape.Consequently, the light bundles generated by the illumination module mayalso have a rectangular shape in various embodiments. The light bundlesproduced by the illumination module 204 may be transmitted to the lightvalve device 206, which may selectively control the amount of light thatis transmitted or reflected to the projection lens 208.

The light valve device 206 may direct and control the amount of each ofthe light bundles being transmitted or reflected to the projection lens208. Although the light valve device 206 depicted in FIG. 2 is beingdepicted as a transmissive type of a light valve device that selectivelyallows light bundles to pass through, in other embodiments, the lightvalve device 206 may be a reflective type of light valve device thatselectively reflects light bundles to the projection lens 208 via, forexample, a mirror as depicted in FIG. 1. The light valve 206 may be, forexample, a digital micromirror device (DMD), a reflective liquid crystalon semiconductor (LCOS) array device, a liquid crystal device (LCD)light valve, and the like.

The control block 202 may be employed to control light sources (notdepicted) that may be included in the illumination module 204 and thelight valve device 206 based on pixel data of images received by thecontrol block 202. By controlling the operation of both the lightsources of the illumination module 204 and the light valve device 206,the light valve device and the light sources may operate in acomplementary manner. In some embodiments, the pixel data may beprovided by, for example, an external computing/media device or anintegrated TV tuner (through, for example, an input interface). In theseembodiments, the control block 202 may cause the light sources to bedriven sequentially. That is, the light sources may be prompted by thecontrol block to emit, for example, light bundles of various colors inalternating sequence. In various embodiments, the control block may beimplemented employing a general-purpose processor/controller, anapplication specific integrated circuit (ASIC), or a programmable logicdevice (PLD).

FIG. 3 depicts the illumination module of FIG. 2, in further detail,according to some embodiments. For the embodiments, the illuminationmodule 300 includes an integrating tunnel (i.e., light tunnel) 302having an output end 304, a far end 306 and side surfaces 308 thatintersects the output end 304 and the far end 306. For the embodiment,the side surfaces 308 are flat surfaces. The output end 304 being theportion of the integrating tunnel 302 that may output light bundles ofdifferent colors associated with different wavelengths. Three lightsource units 310A, 310B and 310C are optically coupled to one of theside surfaces 308. In brief, a light source unit 310A, 310B and 310C maydirect light into the integrating tunnel 302. In various embodiments,the three light source units 310A, 310B and 310C are a combination of ared light source unit, a blue light source unit and a green light sourceunit. Note that although the light source units 310A, 310B and 310C aredepicted as having circular shapes, the light source units 310A, 310Band 310C may actually be of any shape and is depicted here as having acircular-like shape for illustrative purposes only.

The three light source units 310A, 310B and 310C may be positioned andoptically coupled to a side surface 308 such that they are substantiallyaligned from the far end 306 to the output end 304 of the integratingtunnel 302. That is, the light source units 310A, 310B and 310C may bepositioned along an axis 312 that extends from the far end 306 to theoutput end 304 of the integrating tunnel 302. In other embodiments, oneor more of the three light source units 310A, 310B and 310C may beoff-set from the axis 312 so that one or more of the three light sourceunits 310A, 310B and 310C are not aligned along the axis 312 and mayonly be substantially aligned along the axis 312 as indicated by 314. Inyet other embodiments, the light source units 310A, 310B and 310C may belocated on different side surfaces 308 of the integrating tunnel 302.

The three light source units 310A, 310B and 310C, may each comprise ofmultiple components including, for example, a solid state light sourcesuch as an LED, and other optical components. These other opticalcomponents, such as prisms, may be used to redirect the light bundlesproduced by the light source into the integrating tunnel so that thelight bundles may enter the tunnel at angles that may be, for example,most efficient in producing output light from the integrating tunnel302.

Each of the three light source units 310A, 310B and 310C may outputdifferent color light bundles of different wavelengths and project thelight bundles into the integrating tunnel 302. In various embodiments,the three light source units 310A, 310B and 310C, may include a redlight source unit, a blue light source unit and a green light sourceunit. These light source units correspond to the primary colors of red,blue and green. In other embodiments, however, the three light sourceunits 310A, 310B and 310C may output light bundles of other colors suchas, for example, yellow, cyan, white and magenta.

According to one embodiment, the most efficient light source unit of thethree light source units 310A, 310B and 310C may be located furthestaway from the output end 304 while the least efficient light source unitmay be located nearest to the output end 304. Such a scheme may assurethat the different colored light bundles generated by the illuminationmodule 300 generate a better color balance. That is, light thatpropagates through an integrating tunnel may have a tendency toattenuate due to, for example, leakage of the light from the integratingtunnel. Therefore, generally the further the light has to propagatethrough the integrating tunnel, the greater the attenuation of thepropagating light. Balance may be achieved when the proper ratio of thecombined colors are produced and mixed to get a desired color producedby their combination. For example, the proper ratio of red, green, andblue will produce a desirable shade of white. Thus, in order to generatea better balance of different color light bundles, the most efficientlight source unit may be located furthest away from the output end 304while the least efficient closest to the output end 304. This may resultin minimal attenuation of the least available color and therefore mayallow the maximum amount of balanced combined light to be emitted.

To illustrate, suppose the three light source units 310A, 310B and 310Cproduces three different primary colors, red, blue and green. Supposefurther that the light source unit that produces the green light is themost efficient (e.g., has excess green light relative to the desiredbalance proportion), while the red light the least efficient. Then, inorder to generate light bundles closer to the desired balance, the greenlight source unit may be located furthest from the output end, the redlight source unit closest to the output end and the blue light sourcelocated in the middle. Further attenuation may be required to attain theratio for the desired color balance. By minimizing the attenuation ofthe least available color, the maximum total amount of balanced combinedcolor may be achieved.

In the foregoing description, for ease of understanding, surface 308 isreferred to as the side surface. Surface 308 may also be referred to astop or bottom surface, as the qualification of the location of thesurface is merely a function of the point of view from where theintegrating tunnel 302 is described. Accordingly, the reference shouldnot be read as limiting on the invention, and in the context of thelocation of the surface of the integrating tunnel, the terms “topsurface”, “bottom surface” and “side surface” are interchangeable.

Moreover, for ease of understanding, the integrating tunnel 302 of FIG.3 is depicted as having a long square or rectangular shape. However, inother embodiments, the integrating tunnel 302 may have a cylindricalshape or other shape type. If the integrating tunnel is cylindricallyshaped, then there may only be one side surface 308 that completelyencircles the cylindrical shaped integrating tunnel. The integratingtunnel 302 may be hollow with walls or a solid tunnel. If theintegrating tunnel 302 is hollow, then it may comprise of a plurality ofexternal walls made of, for example, mirrors and/or a transparentmaterial such as glass. If the integrating tunnel 302 is a solid tunnelthen it may comprise substantially of transparent material such as glasshaving characteristics that may provide internal reflection of lightthat may propagate through the tunnel. In either cases (i.e., hollow orsolid), the surface is simply just “surface” without the distinction ofbeing “top”, “bottom” or “side”. Further, addition components may bepresent within the integrating tunnel such as mirrors and dichroicfilters.

In various embodiments, the far end 306 may be a reflective end. Forthese embodiments, the far end 306 may be comprised of a mirror, adichroic filter or some other reflective surface that reflects lightwithin the integrating tunnel 302 and may prevent light within thetunnel from escaping out of the far end 306. In some embodiments, thefar end 306 comprises of a reflective surface that only reflects butdoes not allow light to pass through such as a mirror. In thoseembodiments, the far end 306 may be an optically sealed end that may notallow light to be introduced through the far end 306. In otherembodiments, however, the far end 306 may be comprised of a material ora component such as a dichroic filter that both reflect light and allowscertain types of light to pass through. For these embodiments, light maybe introduced through the far end 306. In yet other embodiments, the farend 306 may not include any internally reflective surfaces.

The integrating tunnel 302 may be implemented in a projection system tocreate a uniform illumination pattern with the same dimensionalproportions as the final desired images according to some embodiments.Such an integrating tunnel 302 may operate on the principle of multiplereflection, wherein transmitted light that propagates through thetunnels may reflect off of internal interfaces of the integratingtunnels such that light bundles of substantially uniform intensity maybe emitted from the output end 304 of the integrating tunnel 302.

FIG. 4A depicts one of the light source units 310A, 310B and 310C, infurther detail, and the integrating tunnel 302 of FIG. 3, according tosome embodiments. As briefly described above, a light source unit 310A,310B and 310C may include a light source 402 and an optical couplingdevice 404 such as a prism or a mirror. In these embodiments, the lightsource unit 310A, 310B and 310C may be optically coupled to theintegrating tunnel 302 via an air gap 406 that is interposed between theintegrating tunnel 302 and the light source unit 310A, 310B and 310C. Invarious embodiments, the optical coupling device 404 and the air gap 406represents two different mediums having two different indices ofrefraction.

The light source 402 may generate light bundles of a particular colorsuch as a primary color. The light source 402 may be, for example, asolid state device such as a light emitting diode (LED), a laser diode,and the like. Light bundles generated by the light source 402 may bedirected into the optical coupling device 404, which may channel thelight bundles into the integrating tunnel 302.

The optical coupling device 404 may or may not redirect the lightbundles generated by the light source 402 such that the light bundlesenters the integrating tunnel 302 at a different angle than they wouldhave in the absence of the optical coupling device 404. The opticalcoupling device 404 may be, for example, a prism, mirror, fiber optics,and the like.

The air gap 406 may reduce internal reflection losses of the integratingtunnel 302 in accordance with some embodiments. That is, in someembodiments, the difference in the refractive index of the air in theair gap 406 and the integrating tunnel material (e.g., glass) may resultin reducing the amount of light (already propagating through theintegrating tunnel) that may escape. If the air gap 406 were notpresent, the optical coupling device 404 would contact with theintegrating tunnel 302. Because the optical coupling device 404 andintegrating tunnel 302 have closer indices of refraction, in such asituation, some of the light inside the integrating tunnel 302 wouldpass into the optical coupling device 404 instead of internallyreflecting. Therefore, by placing an intermediate medium (i.e., air gap406) with a different index of refraction between the optical couplingdevice 404 and the integrating tunnel 302, internal reflection lossesmay be reduced.

In other embodiments, the air gap 406 may contain other mediums otherthan air that has a refractive index that is different from therefractive index of the material comprising the optical coupling device404, the integrating tunnel 302 and/or the integrating tunnel walls. Forexample, in various other embodiments, other gases may occupy the gap orspace between the integrating tunnel 302 and the light source unit 310A,310B and 310C. Thus, the term “air gap” is used herein to describe a gapthat is at least partially filled with composition or compositionshaving a different index of refraction from the index of refraction ofthe optical coupling device 404, the integrating tunnel 302 and/or itswalls.

Referring to FIG. 4B, which depicts the light source unit andintegrating tunnel of FIG. 4A, in further detailed, according to someembodiments. Note that FIG. 4B, in addition to depicting the lightsource unit and integrating tunnel of FIG. 4A in detail, may alsorepresent an illumination module comprising of a single light sourceunit coupled to a side surface of an integrating tunnel according tovarious embodiments. For the embodiments, a light source unit 310A, 310Band 310C may include a light source, in this case, an LED 408, and anoptical coupling device, in this case, a prism 410. The prism 410 may beoptically coupled to the LED 408 and to a side surface 308 of theintegrating tunnel 302 through an air gap 406 that may be interposedbetween the prism 410 and the side surface 308 of the integrating tunnel302. The prism 410 when employed in such a manner may be referred to asan air-gap prism. For these embodiments, a dichroic filter 412 may bepositioned within the integrating tunnel 302 to reflect light bundlestransmitted into the integrating tunnel 302 by the LED 408 via the prism410. Although not shown, the integrating tunnel 302 may further becoupled with other light source units.

For the embodiment, the LED 408 may generate and direct light bundles ofa particular color into the prism 410. The prism 410 receives the lightbundles from the LED 408 and may or may not redirect the received lightbundles such that the light bundles enter the integrating tunnel 302 ata different angle than they would have entered if the prism 410 wereabsent. The light bundles entering the integrating tunnel 302 mayreflect off the dichroic filter 412 in such a way that the light bundlespropagates substantially towards the output end of the integratingtunnel. That is, the light bundles may reflect off the dichroic filter412 and may propagate directly towards the output end of the integratetunnel (as depicted by 414) or at shallow angles relative to theinternal interface 416 of the integrating tunnel 302 (as depicted by418) such that at least a portion of the light bundles are reflectedgenerally towards the output end rather than being transmitted out ofthe integrating tunnel 302. The dichroic filter 412 may further allowlight bundles outputted by other light source units to pass through (asdepicted by 420).

The prism 410 may be physically coupled to the side surface 308 of theintegrating tunnel 302 using various techniques including, for example,using an adhesive that may or may not have the same refractive index asthe prism 410 applied minimally at the periphery of the prism 410. Theprism 410 may receive light bundles outputted by the LED 408 andredirect the light bundles into the integrating tunnel 302 at an angledifferent from the angle they would have entered into the integratingtunnel 302 in the absence of the prism 410.

According to one embodiment, the dichroic filter 412 (or its surfaces)may be positioned within the integrating tunnel such that it is at anangle of about 30 degrees from a plane 422 perpendicular to the internalinterface 416 of the integrating tunnel 302 as indicated by 423. Inother embodiments, the dichroic filter 412 may be at an angle of 45degrees or some other angle from the plane 422. Such orientations mayallow light bundles of certain wavelengths to pass through (as depictedby ref. 420) while reflecting light bundles of other wavelengths (asdepicted by refs. 414 and 418).

Note that if the LED 408 represents the light source of a light sourceunit that is located furthest away from the output end (e.g., the lightsource unit 310C of FIG. 3) then the dichroic filter 412 may be replacedby a mirror or some other component having a reflective surface in someembodiments. This may be particularly true, for example, when there isno additional light source or light source unit that is located on thefar end side of the dichroic filter 412 (or reflective surface).

According to various embodiments, an air gap 406 may be interposedbetween the prism 410 and the side surface 308 of the integrating tunnel302. Placing an air gap between the prism 410 and the side surface 308of the integrating tunnel 302 may improve the internal reflectiveproperties of the integrating tunnel 302. As a result, the loss of lightor light leakage from the integrating tunnel 302 through the sidesurface 308 may be reduced or completely eliminated and may result inthe integrating tunnel having total internal reflection.

Referring to FIG. 5 depicting a illumination module 500 with two lightsource units 502 and 504 (a first and a second light source unit) thatare optically coupled to a side surface 506 of an integrating tunnel508, according to some embodiments. For these embodiments, each of thelight source units 502 and 504 comprises of an LED 510 and 512 (a firstand a second light source) and a prism 514 and 516 (a first and a secondoptical coupling device). An air gap 516 is interposed between the lightsource units 502 and 504 and the side surface 506 of the integratingtunnel 508. For these embodiments, the integrating tunnel 508 includestwo dichroic filters 518 and 520. In addition to the side surface 506,the integrating tunnel 508 having an output end 522 and a far end 524.Although not depicted, for the embodiments, the integrating tunnel 508may be coupled with one or more additional light source units located atthe far end 524 portion of the integrating tunnel 508. For example, anadditional one or more light source units may be optically coupled tothe far end 524 of the integrating tunnel 508 if, for example, the farend 524 comprises of a dichroic filter rather than a mirror.

The light bundles generated by LED 510 (first light source) istransmitted through the prism 514 (first optical coupling device) intothe integrating tunnel 508 and reflected off of the first dichroicfilter 518 directly or indirectly (not shown) towards the output end 522of the integrating tunnel 508. Similarly, the light bundles generated byLED 512 (second light source) is transmitted through the prism 516(second optical coupling device) into the integrating tunnel 508 andreflected off of the second dichroic filter 520 directly or indirectly(not shown) towards the output end 522 of the integrating tunnel 508 andthrough the first dichroic filter 518.

At this point, it should be noted that the light source (i.e., LED) andthe optical coupling device (i.e., prism) of each of the light sourceunits 502 and 504 may be replaced with other components in various otherembodiments. For example, in some embodiments, one or both of the LEDsmay be replaced with laser diodes while one or both of the prisms may bereplaced with mirrors.

FIG. 6 depicts an illumination module 600 with three light source units602, 604 and 606 that are optically coupled to a side surface 608 of anintegrating tunnel 610, according to some embodiments. For theseembodiments, each of the light source units 602, 604 and 606 comprisingof an LED 612, 614 and 616 (a first, a second and a third light source)and a prism 618, 620 and 622 (a first, a second and a third opticalcoupling device). An air gap 624 may be interposed between the lightsource units 602, 604 and 606 and the side surface 608 of theintegrating tunnel 610. The integrating tunnel 610 includes threedichroic filters 626, 628 and 630. In other embodiments, a mirror orother reflective surfaces may replace the third dichroic filter 630. Inaddition to the side surface 608, the integrating tunnel 610 having anoutput end 632 and a far end 634, in this case, the far end 634comprising of the third dichroic filter 630. Although not depicted, theintegrating tunnel 610 may be coupled with one or more additional lightsource units located at the far end 634 portion of the integratingtunnel 610. For example, an additional one or more light source or oneor more light source units may be optically coupled to the far end 634of the integrating tunnel 610 in some embodiments. In other embodiments,however, if the far end 634 is a light sealed far end such as when thefar end is comprised of a mirror than no additional light sources orlight source units may be coupled to the far end 634.

Each of the light source units 602, 604 and 606 may transmit lightbundles of different colors such as primary colors into the integratingtunnel 610. The light bundles that are transmitted into the integratingtunnel 610 may reflect off of the dichroic filters 626, 628 and 630 andpropagate either directly towards the output end 632 of the integratingtunnel 610 as depicted by refs. 636, 638 and 640 or indirectly towardsthe output end 632 (not shown). If the light bundles are propagatingindirectly towards the output end 632, then the light bundles may bepropagating at shallow angles relative to the internal interfaces 642 ofthe integrating tunnel 610. This may result in the light bundles beingefficiently reflected off the internal interfaces 642 of the integratingtunnel 610 and propagating in the general direction of the output end632 of the integrating tunnel 610.

Again, it should be noted that the light source (i.e., LED) and theoptical coupling device (i.e., prism) of each of the light source units602, 604 and 606 may be replaced with other components in various otherembodiments. For example, one or more of the LEDs may be replaced with,for example, laser diodes, while one or more of the prisms, for example,may be replaced with mirrors.

According to one embodiment, the most efficient light source unit of thethree light source units 602, 604 and 606 may be located furthest awayfrom the output end 632. Such architecture may assure that the differentcolored light bundles generated by the illumination module 600 aregenerated in balance. Similarly, for the same reasons, the leastefficient light source unit of the three light source units 602, 604 and606 may be located nearest to the output end 632. In other embodiments,other light sources may be optically coupled to the integrating tunnel616. For example, additional light sources may be coupled to the far end634 of the integrating tunnel 610.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat a wide variety of alternate and/or equivalent implementationscalculated to achieve the same purposes may be substituted for thespecific embodiments shown and described without departing from thescope of the present invention. This application is intended to coverany adaptations or variations of the embodiments discussed herein.Therefore, it is manifestly intended that this invention be limited onlyby the claims and the equivalents thereof.

1. (canceled)
 2. The illumination module of claim 4, wherein at leastone of the plurality of light source units comprises a selected one of alight emitting diode and a laser diode.
 3. An illumination module,comprising: an integrating tunnel having an output end to output lightin an output direction; three light source units optically coupled tothe integrating tunnel to output three different color light bundles ofdifferent wavelengths into the integrating tunnel from a directionnonparallel to the direction of the output direction; and wherein a mostefficient of the three light source units is located furthest away fromthe output end.
 4. An illumination module, comprising: an integratingtunnel having an output end to output light in an output direction;three light source units optically coupled to the integrating tunnel tooutput three different color light bundles of different wavelengths intothe integrating tunnel from a direction nonparallel to the direction ofthe output direction; and wherein a least efficient of the three lightsource units is located nearest to the output end.
 5. The illuminationmodule of claim 4, wherein the three light source units are acombination of a red light source unit, a blue light source unit and agreen light source unit.
 6. The illumination module of claim 4, whereinat least one of the three light source units comprises an opticalcoupling device, the optical coupling device optically coupled to a sidesurface of the integrating tunnel that intersects the output end.
 7. Theillumination module of claim 6, wherein the optical coupling device is aprism.
 8. The illumination module of claim 7, wherein the integratingtunnel comprises at least one dichroic filter adaptively positionedwithin the integration tunnel to reflect light transmitted from theprism.
 9. The illumination module of claim 4, wherein the integratingtunnel comprises a dichroic filter adaptively positioned within theintegrating tunnel to reflect light bundles transmitted from one of thethree light source units.
 10. (canceled)
 11. The projection system ofclaim 13, wherein at least one of the three light source units comprisesa selected one of a light emitting diode and a laser diode.
 12. Aprojection system, comprising: a projection lens; an integrating tunneloptically coupled to the projection lens, the integrating tunnel havingan output end to output light in an output direction; three light sourceunits optically coupled to the integrating tunnel to output threedifferent color light bundles of different wavelengths into theintegrating tunnel from a direction nonparallel to the direction of theoutput direction; and wherein a most efficient of the three light sourceunits is located furthest away from the output end.
 13. A projectionsystem, comprising: a projection lens; an integrating tunnel opticallycoupled to the projection lens, the integrating tunnel having an outputend to output light in an output direction; three light source unitsoptically coupled to the integrating tunnel to output three differentcolor light bundles of different wavelengths into the integrating tunnelfrom a direction nonparallel to the direction of the output direction;and wherein a least efficient of the three light source units is locatednearest to the output end.
 14. The projection system of claim 13,wherein the three light source units are a combination of a red lightsource unit, a blue light source unit and a green light source unit. 15.The projection system of claim 13, wherein at least one of the threelight source units comprises an optical coupling device, the opticalcoupling device optically coupled to a side surface of the integratingtunnel that intersects the output end.
 16. The projection system ofclaim 15, wherein the optical coupling device is a prism.
 17. Theprojection system of claim 13, wherein the integrating tunnel comprisesof a dichroic filter adaptively positioned within the integrating tunnelto reflect light bundles transmitted from one of the three light sourceunits.
 18. The projection system of claim 13, wherein the projectionsystem further comprises a light valve device optically coupled to theintegrating tunnel to direct light outputted by the integrating tunnelto the projection lens.
 19. The projection system of claim 13, whereinthe projection system further comprises: a processor coupled to thethree light source units; and an input interface coupled to theprocessor to facilitate input to the processor pixel data of an image.20. (canceled)
 21. In a projection system, a method of operation,comprising: receiving pixel data of an image to be projected;controlling three light source units to transmit three different colorlight bundles of different wavelengths into an integrating tunnel from adirection nonparallel to output direction of light outputted by theintegrated tunnel, wherein a most efficient of the three light sourceunits is located furthest away from an output end of the integratingtunnel; and wherein said controlling of three light source unitscomprises controlling the light sources to alternate in transmitting thedifferent color light bundles at different points in time as needed forthe projection of the image.
 22. The method of claim 21 furthercomprises controlling a light valve device in a complementary manner.23. The method of claim 21, wherein said controlling of three lightsource units comprises controlling a combination of a red light sourceunit, a blue light source unit and a green light source unit.
 24. Theillumination module of claim 3, wherein at least one of the plurality oflight source units comprises a selected one of a light emitting diodeand a laser diode.
 25. The illumination module of claim 3, wherein thethree light source units are a combination of a red light source unit, ablue light source unit and a green light source unit.
 26. Theillumination module of claim 3, wherein the integrating tunnel comprisesa dichroic filter adaptively positioned within the integrating tunnel toreflect light bundles transmitted from one of the three light sourceunits.
 27. The projection system of claim 12, wherein at least one ofthe three light source units comprises a selected one of a lightemitting diode and a laser diode.
 28. The projection system of claim 12,wherein the three light source units are a combination of a red lightsource unit, a blue light source unit and a green light source unit. 29.The projection system of claim 12, wherein the integrating tunnelcomprises of a dichroic filter adaptively positioned within theintegrating tunnel to reflect light bundles transmitted from one of thethree light source units.
 30. In a projection system, a method ofoperation, comprising: receiving pixel data of an image to be projected;controlling three light source units to transmit three different colorlight bundles of different wavelengths into an integrating tunnel from adirection nonparallel to output direction of light outputted by theintegrated tunnel, wherein a least efficient of the three light sourceunits is located nearest to an output end of the integrating tunnel; andwherein said controlling of three light source units comprisescontrolling the light sources to alternate in transmitting the differentcolor light bundles at different points in time as needed for theprojection of the image.
 31. The method of claim 30 further comprisescontrolling a light valve device in a complementary manner.
 32. Themethod of claim 30, wherein said controlling of three light source unitscomprises controlling a combination of a red light source unit, a bluelight source unit and a green light source unit.